DESCRIPTION (Verbatim From Applicant's Abstract): Our novel and innovative approach for improving the biostability of thermoplastic polyurethane Consists of chemically modifying tpu and crosslinking it with electron beam radiation. The objective of this Phase I proposal is to evaluate, using a combination of in vivo and in vitro studies, the degree to which this innovative approach improves the biostability of TPU. An improvement in the blostability of TPU would have wide application in biomedical devices especially in Cardiac Pacemakers. Cardiac pacemakers are medical devices, which regulate cardiac rhythmic disorders. Pacemakers comprise a generator, connected to an insulated lead, which is implanted in the heart. Electrical pulses transmitted via the lead are timed to stimulate the heart muscle in a regulated manner. Pacemaker failures may result from deterioration of the pacemaker lead wire insulation. A tailed lead must be surgically replaced. The availability of a cardiac pacemaker wire insulation with increased implant lifetime would be of great value to the medical profession, Such improved leads would eliminate or greatly reduce the requirement for costly and risky surgical lead replacement procedures. A successful demonstration of increased biostability of cross-linked tpu would encourage commercialization of pacemakers utilizing crosslinked tpu insulated leads. PROPOSED COMMERCIAL APPLICATION: Potential commercial applications include pacemaker leads, Vascular grafts, Artifical hearts, Neurological leads, Arterio-venous dialysis shunts, Implantable defibrillators, Wound dressings, Cardiac catheter, Urethral catheters Mammary prostheses, IV bags and tubing, Chemotherapy tubing, Joint protheses, Cardiac valves, and cardiac assist devices such as aortic balloon pumps.